The present invention relates to carbon products and other pigments and polymers and more particularly relates to the coating of pigment products with polymers. The present invention further relates to the use of aqueous media polymerizations such as emulsion or suspension techniques or solvent based procedures to coat, at least partially, carbon products, such as carbon black and other pigments.
Carbon products, and more specifically, carbon black have been used in a variety of areas as a filler and/or reinforcer. While carbon black can advantageously contribute to the properties of various polymers in which it is present in, carbon black has been shown to contribute to certain detrimental properties such as impact properties, including tensile properties and stress and strain-related properties. In addition, carbon black when included in the polymers is usually added with the use of masterbatches since carbon black can be difficult to disperse in polymers due to its physical properties such as small primary particle size and highly structured aggregates.
Accordingly, developing means to overcome one or more of these above-described problems would be desirable.
In an embodiment of the present invention, the present invention relates to a polymer coated modified carbon product, wherein the polymer at least partially coats a modified carbon product. Preferably, the modified carbon product has at least one organic group attached to the carbon product. The organic group is preferably substituted with an ionic, ionizable, or polar groups which can facilitate the formation of a stable dispersion in an aqueous media. In this embodiment, the polymer partially or fully encapsulates the modified carbon product, or the modified carbon product is the core and the polymer is the shell.
The present invention further relates to a method of making a polymer coated modified carbon product which includes the steps of combining, in an aqueous-based medium, an initiator, at least one monomer, and a modified carbon product. The modified carbon product preferably has at least one organic group attached to the carbon product. Again, the organic group is preferably substituted with an ionic, ionizable, or polar group. The initiator, at least one monomer, and the modified carbon product are then subjected to an emulsion, suspension, or other aqueous based polymerization to form a polymer coated modified carbon product, wherein the monomer is capable of being polymerized in an aqueous environment and the modified carbon product is dispersible or dispersed in the aqueous-based medium. This method also relates to the use of a modified carbon product which can form stable aqueous dispersions and can also physically and/or chemically bond to the polymer formed during the polymerization of the monomers.
The present invention, in addition, relates to a method of making a polymer coated modified carbon product such as that described above, wherein a polymer is prepared separately and is then dissolved in an appropriate organic solvent. A modified carbon product is then combined with the solvent containing the polymer, followed by the removal of the solvent, such as by evaporation or other means.
Further, the present invention relates to a method of making a polymer coated modified carbon product such as that described above, wherein a polymerizable monomer is present in an organic solvent and a modified carbon product is then combined with the solvent containing the monomer, followed by polymerization of the monomer and subsequent removal of the solvent.
The present invention also relates to polymer coated modified pigments.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the present invention, as claimed.